Figure 2.

Breast milk concentration versus plasma concentration at 2 h following a 30 mg oral dose of dextromethorphan in lactating women, ≥ 3 months postpartum. a) Total dextromethorphan (DM) (n=20), b) unbound DM (n=19), c) total dextrorphan (DX) (n=20), and d) unbound DX concentration (n=19) in breast milk (y-axis) and plasma (x-axis). Open circles represent the observed breast milk and plasma concentrations of each subject and the dashed lines represent the best-fitted linear regression line. The equation, R-squared (R²) value, and the p-value of slope deviation from zero of the simple linear regression are reported on each respective graph.